245 Linking Cervical Spinal Cord White Matter Magnetization Transfer Ratio to NIH Toolbox Based Analyses of Motor Function in Degenerative Cervical Myelopathy

INTRODUCTION: Traditional spine imaging technique present disparity between degenerative cervical myelopathy (DCM) disease severity and prognosis. Advancement in spine neuroimaging has unveiled key changes that enhance our understanding of DCM pathogenesis. We investigated region- and tract-specific SC white matter (WM) damage and their relationship to motor deficit in DCM. METHODS: A cohort of 20 DCM and 23 age-matched HC participants were recruited in a cross-sectional study. We utilized a consensus MT-imaging protocol, Spinal cord Toolbox, and objective motor assessment tool battery to assess the extent of WM injury and functional deficits in DCM. The SC WM region- and tract-based MTR were calculated in three different ROIs: maximum compressed level (MCL), caudal uncompressed level (C7), and central region of compression. RESULTS: DCM patients demonstrated significant functional deficits compared to HC in motor assessments. DCM exhibited reduced MTR measures denoting WM injury in the anterior region of the SC and within selected motor tracts in the ROIs. MTR values in reticulospinal, vestibulospinal, and lateral corticospinal tracts were significantly associated with dexterity and grip strength measures. CONCLUSIONS: Our methodology enables precise mapping of ROIs within the SC allowing us to demonstrate an association between tract-specific WM damage and functional motor deficits in DCM patients. Additionally, the observation of decreased MTR measures in seemingly uncompressed SC regions indicates the pathophysiology of DCM that may provide insight into the varying presentations of DCM. Identification of specific WM injury may help better understand DCM deficits that can be targeted for effective interventions to improve patient outcomes